Breech hood and breech bolt lock



June 6, 1950 A. L. CHEVALLIER ETAL 2,510,685

BREECH HOOD AND BREECH BOLT LOCK Filed March 14, 1946 5 Sheets-Sheet 1 O I I m E |H|ll\ g E E P i H N 0 [p N I I g [i w u- 0 i I v: a 1 *"L': z

Inventors Arnold Louis Ohevo l Ii er Stanislaw Sochuczewslu By iheir Attorneys June 6, 1950 A. L. CHEVALLIER ET AL 2,510,685

BREECH HOOD AND BREECH BOLT LOCK 5 Sheets-Sheet 2 Filed March 14, 1946 I Inventors Arnold LouisChevullier Stanislaw Sochuczewski By their Attorneys June 1950 A. L. CHEVALLIER ET AL. 25

BREECH HOOD AND BREECH BOLT LOCK 5 Sheets-Sheet 5 Filed March 14, 1946 061 M \i FYl/L. g H g i D 1 I.

E S w O i +3 .6 z 41 J m V m3 p m IT W F ill I I L m W P S J Tm QUE Inventors Arnold Louis Chevclllier Stanislaw Sochoczewski By their Attorneys June 6, 1950 Filed March 14, 1946 A. L. CH EVALLIER ET AL 2,

BREECH HOOD AND BREE-CH BOLT LOCK 5 Sheets-Sheet 4 lnvenfors 7Arno ld LOUIS Chevulller Sfomslow SOChOCZGWSkl BytheirAflorneys Patented June 6, 1950 BEE-E011 2.9 are BREEQH min-moon Arnold Louis Ghevallien'Maidenhead; and? Stani'slaW-Soohaczews ki, Izondon, England) An elic 19 1 Mgfifi tlf 194.6, Serial .Nnfil' i m me itii Me ci 5 124 ThiSzinvention relates to automatic firearms- Qf" the short barrel -recoil typeand has for its ob ject to provide novel means) for efiecting thebre'ech" aotion.

According to; this invention, in a weapon of the type referred to, the movement Offthe breech holtior reloadingis effiectedby, a hooq or inertiaaqtuated member whichis locked in a position.

covering, the breech, in: the firing position, and; which is unlocked at or near the end ofthe recoil; angliis driverr in arearwarol'directiontby a spring mounted on the magazine tube, and compressed. by the recoil; and'arr'ies thebolt'with it by'rneans of. a o se couplina.

The bolt is preferably lockedin the firing position in ependen y f he hood and. s unlocked: during the rearward' travel of the hood,

' Further features of the invention will-become apparent from the following description given; with reference to the accompanying drawings whichillustra-te the invention as applied" to a. shot gun and rifle.

the r winek Figure I is an elevation andFigure 2is a plan; s 'i of 1. 9 n;

Figures 3 to: 5' are partial sectional elevations withfp arts omitted of the shot, gun, illustrating, he mov ment of, the hood andibreech bolt;

-liligure 6is a sectional elevation, illustrating the, action ofthe cartridge spoon;

Figures 7,8 and 9 are detailsof'the spoon and. associated: parts;

Figures 10; III and; 12 are details of; the hood e k me FigurelB is an elevation andFigure 14' a sectionalgelevation of the breech bolt;

Figure 15 is a segtional elevation and Figure :6. is. a nv r edin e the ckin n c Figure lfTis at rear elevatiqnoithe bolt;

Fi res 1.3}, '9. d 2 r slaec ire an emit elevation, elevation and plan of the crutch;

Figures 21 and 22 ar d ta howi hood recoil buffering ine ans;;-

Figure 23 isan' elevation ofi'thehood;-

F-igure 2% is an elevation of'the; double nut on the end ofthe magazine tube;-

Figures 25' angl-25are details o-fmembers shown in Figure 24;;

Figures" 27* anci 28*are elevations of a breach bolt suitable for a rifle, respectively in locked and-unlocked: position and; Figure 29 is a plan of breech belt of Figures 27'and-28. Referringi irst to- Eigures 1:, 2 anti 3 to 5, a cradle-0r breecl frame receiver "supports; the:

recoiling barrel extension i to which the-berm!" is fixedi A'tubular magazine-'44s attachedtothe receiver- 1* and projects forwagqparallel to; the barrel-32 A cover 5 is QIfOVidQdf over the magazine 4 and is held in place by a clpjilple nut 'fi'z A lug 1 on the bar-rel 3 slides along the magazine i-to assist in guiding thebarrel 35111111; ing its reeoiling and return; movements A ring 8- is slidable on-the magazine 4" and rigiqdy counl'ed to the lug 1: bylinlgs- 9 one oneach side? A- recoil: spring lli surrounds the rearpart of the; magazine. '4 andon recoilis compresseci" betweenthe ring sand a loose ring; I [,gWhich-restsagaipst; the receiver l The breechisnomnally covered by a hoog l2; which can slide longitudinally on the barrel egg tensionzrpins LS on' either sided-"the hood l2 engaging in slots I 4" in the barrelextension 2*. The hood le -has two projections l-fi-at the frontnearthe lower edges of sides to cooperate; with a crutohashown separatelyin Figures 18, l ir and-"20; This crutchoomprises-a ring Iii-to slide:- onthe magazine 4; two arms H extending rearwards fromrthe ring 1&6: anclrfeet- 1 8" on the rear ends-of the 'armsrl'l whichwfeet-press! on the projections; 5a of the'hoow -l When the; barrel skreooils; the lug comnreeses; al-wmaster-spring; 1&2 a ain t h e-mine which tends todnivethes hood;- LZ-rIGQIWflfidS;

During firing and then-1st: pa; of the recoil: the hon out. is, held; in place-be a levenzlm pivoted? on: aiv t andsprev dedimthn praiecti n 2:2: gum, engages behind.- the' ear nd f h hood? he manner n which the lever"! mounted! may belseen hestJromJigpres; lflitQ- 12;in 0011: infl i n" h i' eune eh ands-2s A vw melai L e mpi meu. to slide et-Licens in, the n ce en- I anti: il egit m te-debt arse i ne 2 4, he plu a smsz e bra; n, 2,5 in the e ee 2t: and home the et er m ment n.@flsmhaemsfihm I;- Figure 1. A chamfered head 26 on thenlug s ee aeesi ra. eert at tee-b rrel enterisiee 2 which. cl nn sses, the p u 23 0. 1 reco le t ze me eieiim terelea ood 1.2m wnseaueet de nwa slm. ..Q le r; A0,,

During th eee ithe metiet sprin We em Pressedenemies hehqo l l lbeclswardeassaeu as the, ev Q. relea es A l ll lk ififil it-ea the e e it rq iq s. tQr e eee b1 Hand: when reguired M I The. bree h e t as s Wei table ee itudieel a n ide, he 1 924, t. 51mm separatel iire 1 A e ieamee ..E .%ll 'q&

'e i nee a 34 at the fr m tests;

the bolt on its under side and has two cheeks 32 partly embracing the sides of the bolt. A spring 33 fixed at 34 to the locking piece 3% has a toe '35 pressing against the body of the bolt 29 near the forward end to urge the locking piece 39 downwards, in which position the latter engages a notch in the barrel extension 2 and so locks the bolt in the position shown in Figure 4.

Each check 32 has a cam slot 36 to engage the pin !3 projecting inwards from the respective side of the hood l2. The forward part of the slot 36 is horizontal and the rear part slopes downwards. After the hood l 2 has moved a hort distance rearwards the pins l3 come to the downwardly sloping portions of the slots 36 and raise the locking piece 39. By the time the pins l3 reach the rear ends of the slots 36 the bolt 29 is unlocked, and the hood l2 carries the bolt 29 back with it by virtue of its kinetic energy against the effect of a. recuperator spring 31 (Fi ure 4). The bolt 29 has a recess 38 for the reception of the forward part of the spring 31. The spring 3'! surrounds a rod 39 which assists in the ejection of the spent cartridge.

A firing pin 49 is slidably mounted in the bolt 29 and has a depending rear portion 4|. A ridge 42 at the rear end of the locking piece 39 engages the front of the portion 4| when the bolt 29 is unlocked and so locks the firing pin 49 in its retracted position. In moving to the bolt-unlocking position the ridge 42 of the locking piece 39-retracts the firing pin 49 prior to looking it. Referring more particularly to Figures 6 to 9. as the bolt 29 reaches its rearmost position. a depending rear portion of the firing pin. as hereinafter set forth. or the underside of the bolt 29 engages the sloping end of a lever 43. pivoted at 44. which depresses through a link 45 the rear end of a spoon feed arm 46 pivoted at 41 and so swings the front end of the arm up against the pressure of a spring 48. In this position a safety catch 2'! carried .by the lever 43 engages in a recess in the sear of the trigger mechanism thereby looking it.

A spring lever pawl 49 in the side of the receiver I engages in a ring 59 on the underside of the arm 46 and holds the arm 46 in its raised position (as shown in broken lines in Figure 6) during the first part of the return of the hood and bolt. Meanwhile the cartridge 5! carried by the spoon arm 46 is engaged by an extractor on the side of the bolt 29, and is pushed into the chamber. A raised portion 49a at the front end of the lever pawl 49 is engaged by a depending lug 53 on the side of the hood l2 (see Figure 23) when the cartridge 5| has partly entered the chamber. The lever 49 is thereby tilted to release the pawl from the ring 59 on the spoon arm 46, and the arm is returned to its lower position (as shown in full lines in Figure 6) by the spring 48 ready to receive a fresh cartridge in the spoon.

The spoon arm 46 carries near its front end a spoon 54, pivoted to the arm 46 at 55, adapted to receive the cartridge. The position of the pivot 55 and the distribution of weight in the spoon 54 are so adjusted that when there is no cartridge in the spoon 54 the rear end of the same occupies the position shown in Figure 6. Thus if the arm 46 is raised while the spoon 54 is empty, the rear end 56 projects into the path of the bolt 29 and arrest it in the position shown in the dotted lines in Figure 6. When the spoon 54 carries a cartridge, the rear end 56 is depressed out of the path of the bolt 29. In this way the breech is kept open when both chamber and magazine are empty.

The hammer and trigger gear are of normal construction, but the cooking of the hammer 51 is efiected in two stages. A roller 58 is mounted on the barrel extension 2, which half cooks the hammer 51 (as shown in Figure 4) during the recoil. Cooking is completed by the depending rear portion 4| of the firing pin 49 during the rearward travel of the bolt 29.

The impact of the hood on its return to the firing position is taken, through the crutch IT, by the spring l9 thereby converting this element into a forward bufier controlling the run out.

The rod 39 protrudes from the face of the bolt 29, when the latter reaches its rearmost position and acts as an ejector. Another ejector consisting of a spring-urged plunger projecting from the face of the bolt is mounted in a boring in the upper right hand side of the bolt. Figure 5 shows the position at the moment of ejection of the spent cartridge 5|.

Figure 4 shows the position when the barrel 3 and barrel extension 2 have commenced the recoil and have half cooked the hammer 51, but before the hood 12 has been unlocked.

Figure 5 shows the position when the hood 12 has unlocked the bolt 29 by the sliding movement of the pins 13 in the cam slot 35 and the hood i2 has carried the bolt 29 rearwardly to the cartridge ejecting position. The hammer 5'1 has been fully cooked by the depending rear portion ii of the firing pin 49.

Figure 3 shows the position when the hood I2 and bolt 29 have reached their rearmost position, the cartridge 5i having been raised by the spoon arm. For the sake of clarity the spoon arm and associated mechanism are omitted from Figures 3 to 5.

hood I2 and being adapted to slide in a groove 6i in the top of the barrel extension 2. The end of the groove iii is undercut at 62. When the hood [2 reaches the end of its rearward movement, the strip 59 engages in the undercut porhold 52 thereby arresting the travel of the hood l2 and cushioning the shock.-

As shown in Figures 1, 2 and 23, may be provided with thicker portions 53 to augment the weight of the hood and provide a grip for hand movement of the hood when required.

To make the mechanism suitable for a rifle relying on a box magazine for its supply of ammunition, certain modifications are required, mainly to the bolt and the locking piece. These will now be described with reference to Figures 2'? to 29. The most evident change is the location of the locking piece on the top of the bolt.

The bolt 54 has two lugs on each side near the two ends to engage guide grooves in the barrel extension. The locking piece 66 comprises two side portions 61 to fit recesses 58 in the bolt 64 and a flat portion 69 uniting the side portions and lying on top of the bolt 64 when in the unlocking position (Figure 28). The locking piece 56 is pivoted at 16 on the bolt 64 near its front end. Screws H engage by their points grooves (not shown) in the sides of the bolt 64 to limit the movement of the locking piece 66. Lugs 12 on the sides of the locking piece 66 are in alignment with the lugs 65 in the unlocking position.

When the locking piece 66 is in its raised or lookthe hood [2 ing position (Figure 27) to which it is urged by the spring 13 bearing on top of the bolt 64 the lugs 12 rest against shoulders in the barrel extension to lock the bolt 64 in the firing position. At the same time the rear end of the looking piece 66 bears against a shoulder at the top of the barrel extension.

The movement of the locking piece 66 into its locking and unlocking position is effected in the same way as in the shot gun by means of grooves 14 in the side portions 61 of the locking piece 66.

Referring now to Figures 24 to 26, these show details of the construction of the double nut 6 which serves the dual purpose of holding the magazine cover 5 in position against the re ceiver I (see Figures 1 and 2) and of adjusting the compression of a front buffer spring 82. The double nut 6 consists of an inner nut 15 which screws onto the magazine 4, and the inner end of which bears against the buffer spring 82, and an outer nut 16 which screws on to the inner nut 15. The rear end of the nut 16 is provided with a flange 11 the rear face of which carries two points or teeth 18 carried on the end of spring members 19. Secured to the front face of the magazine cover 5 is a ring 80 having therein a number of perforations 8! into which the teeth 18 are adapted to engage. In this way unintentional turning of the nut 16 is prevented.

Referring again to Figure 3, the cartridges 5| in the magazine tube 4 are moved into the spoon by means of a follower 83 urged by a spring 84. To prevent the follower passing into the receiver I when the magazine tube 4 is empty, the follower 83 is provided with a split spring band 85 adapted to spring into a groove 86. If desired the follower 83 may be provided with a rod 81 adapted to protrude through the double nut 6 to give an indication of how many cartridges the magazine contains.

We prefer that the springs used in the firearm should be made of steel containing about 2.5 to 2.75% of beryllium since this material has been found to have greatly superior resistance to repeated percussion.

What we claim is:

-1. An automatic firearm of the recoiling barrel type in which there is a breech frame, a receiver on which the breech frame is slidably mounted and a bolt in said breech frame, in combination with a hood slidably mounted on the breech frame, means for locking the hood to the receiver in the firing position where it covers the breech, a magazine tube and a spring thereon compressed by the recoil and adapted to drive the hood rearwardly, means on the breech frame to unlock said locking means at or near the end of the recoil, a loose coupling connecting the bolt and the hood, whereby rearward movement of the hood relative to the breech frame carries the bolt rearwards within the breech frame to the reloading position, and a recuperator spring compressed on the rearward travel of the hood and bolt which serves to return both these members to the firing position.

2. An automatic firearm of the recoiling barrel type according to claim 1 in which the loose coupling has pins projecting inwards from the hood, in combination with a locking piece having side portions for locking the bolt in the firing position independently of the hood, said side portions having cam grooves which engage the coupling pins, the cam grooves having longitudinal portions to permit relative movement of the hood and the bolt during the recoil and sloping portions to effect unlocking of the bolt during the rearward travel of the hood.

3. An automatic firearm of the recoiling barrel type according to claim 1 in which the loose coupling has pins projecting inwards from the hood, in combination with a locking piece com prising side portions pivotally mounted near the front face of the bolt which engages a notch in the breech to lock the bolt to the breech in the firing position, said side portions having cam grooves which engage the coupling pins, the cam grooves having longitudinal portions to permit relative movement of the hood and the bolt during the recoil and sloping portions to effect pivoting of said locking piece out of engagement with the said notch to effect unlocking of the bolt during the rearward travel of the hood.

4. In an automatic firearm of the recoiling barrel type according to claim 1, the combination of a receiver, the magazine tube being mounted thereon, a master spring surrounding the magazine tube, a lug secured to the barrel and surrounding the magazine tube, a crutch comprising a ring surrounding the magazine tube and two arms having feet adapted to engage projections on the front of the hood, said master spring being located between said lug and said crutch ring so that the master spring is compressed on recoil and serves to drive the hood rearwardly when the hood is unlocked.

5. In an automatic firearm of the recoiling barrel type according to claim 1, a receiver, a lever pivoted to the receiver, a, projection on the lever adapted to engage behind the hood and lock it in its forward position, and a plug housed within the receiver and connected to the lever by a pin, in combination with a chamfered head on said plug, an extension of the barrel and a part on the barrel extension adapted to engage said chamfered head during recoil, whereby said plug is depressed to effect depression of said projection to release the hood for rearward movement.

ARNOLD LOUIS CHEVALLIER. STANISLAW SOCHACZEWSKI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,544,566 Eickhoff July 7, 1925 1,564,014 Pedersen Dec. 1, 1925 1,852,411 Henry Apr. 5, 1932 2,278,589 Rutherford Apr. 7, 1942 2,342,703 Simpson Feb. 29, 1944 

